1. Field of the Invention
This invention relates to a joint construction for metal sheets which is made by utilizing a plastic working deformation of the metal sheet.
2. Description of the Prior Art
Various joint constructions have been proposed heretofore for joining metal sheets together, including welding, riveting, crimping, or curling techniques.
For parts which are to be exposed on the outside of an article, however, it is desirable to dispense with a coating operation by using coated steel sheets. In that case, it is not desirable to employ a joint construction based on welding, because it would be necessary to coat the joined portions again after welding.
On the other hand, in a joint construction using rivets, the use of rivets in addition to metal sheets to be joined is required, involving performing a sequence of troublesome operations for forming the joint construction, such as drilling holes for receiving rivets, inserting rivets in the drilled holes, and up-setting the rivets. Moreover, special equipment must be used.
Also, in a joint construction utilizing plastic deformation as in a crimping or curling operation, a subsequent coating operation can be avoided by using coated steel sheets. However, a special mold and equipment are required for forming the joint.